What is the sum of the first 35 terms in the series 7 + 9 + 11 + a. 29 c. 1645 b. 1399 d. 1435

If a sequence is arithmetic or geometric there are formulas to find the sum of the first nn terms, denoted Sn , without actually adding all of the terms.

(Note that a sequence can be neither arithmetic nor geometric, in which case you'll need to add using brute force, or some other strategy.)

To find the sum of the first nn terms of an arithmetic sequence use the formula,  Sn=[n(a1+an)]/2

where n is the number of terms, a1 is the first term and an is the last term. 

First find the 35th term:

a35=a1+(n-1)(d) = 7+(34)(2) = 75

Then find the sum:

Sn=[n(a1+an)]/2 = [35(7+75)]/2 = 1435

Thus, the answer is:

-3

step-by-step explanation:

a drawing really does here:

so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be).   so point b is at (-2,2).   point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).

now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.

we have the area of the triangle is .5bh=12.5

we know the base length is 5 (ab)

we have the height is (2-y) if you look at your

plug in

.5(5)(2-y)=12.5

solve for y to get the y-coordinate for c

2.5(2-y)=12.5

divide both sides by 2.5 giving:

2-y=5

now subtract 2 on both sides

-y=3

y=-3

the answer to your question is c.)   volcanoes built the mountains and earthquakes tore them down.

step-by-step explanation: